<?php
class Cat{
	public function jiSuan($num1,$num2,$oper){
		$res=0;
		switch ($oper) {
			case '+':
				$res=$num1+$num2;
				break;
			case '-':
				$res=$num1-$num2;
				break;
			case '*':
				$res=$num1*$num2;
				break;
			case '/':
				$res=$num1/$num2;
				break;
		}
		return $res;
	}

	public function area($lang,$width){
		
		return $lang*$width;
	}
}

?>